pelagic sediment

geology

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July 1, 2026

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Pelagic sediments are deposits found on the deep seafloor, covering about 75% of this area. They accumulate slowly and are primarily composed of the skeletal remains of microscopic marine organisms, such as foraminifera, diatoms, and radiolarians. These biogenic components make up at least 30% of the sediment.123

When these skeletal remains are made of calcium carbonate, they form calcareous oozes, like globigerina ooze. If they are made of silica, they form siliceous oozes, such as radiolarian or diatom ooze. The distribution of these sediments depends on factors like ocean productivity, the dissolution of skeletal material, and dilution by other sediment types. In contrast to continental shelf sediments, pelagic sediments receive very little material from land.231

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Atlantic Ocean
Bottom deposits
…by several inches of normal pelagic sediment. Study of the shells of planktonic foraminifera in these cores shows that the climatic changes, ice ages, and interglacial ages of the last two million years have been recorded in the sediments as alternations of species adapted to cold or to warm water.…
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…by several inches of normal pelagic sediment. Study of the shells of planktonic foraminifera in these cores shows that the climatic changes, ice ages, and interglacial ages of the last two million years have been recorded in the sediments as alternations of species adapted to cold or to warm water.…
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sedimentary rock
General properties of shales
In pelagic (deep-sea) sediments, however, feldspar may be derived from local volcanic sources, whereas quartz may be introduced from the continents by wind, upsetting simple patterns. A large number of accessory minerals occur in shales. Some of these are detrital, but diagenetic or in situ varieties…
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In pelagic (deep-sea) sediments, however, feldspar may be derived from local volcanic sources, whereas quartz may be introduced from the continents by wind, upsetting simple patterns. A large number of accessory minerals occur in shales. Some of these are detrital, but diagenetic or in situ varieties…
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bathyal zone
Bathyal sediments are terrestrial, pelagic, or authigenic (formed in place). Terrestrial (or land-derived) sediments are predominantly clays and silts and are commonly coloured blue because of accumulated organic debris as well as bacterially produced ferrous iron sulfides. Coarser terrigenous sediments are also brought to the bathyal seafloor by sporadic…
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Bathyal sediments are terrestrial, pelagic, or authigenic (formed in place). Terrestrial (or land-derived) sediments are predominantly clays and silts and are commonly coloured blue because of accumulated organic debris as well as bacterially produced ferrous iron sulfides. Coarser terrigenous sediments are also brought to the bathyal seafloor by sporadic…
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